/**
 * Posts an event to all registered subscribers.  This method will return
 * successfully after the event has been posted to all subscribers, and
 * regardless of any exceptions thrown by subscribers.
 *
 * <p>If no subscribers have been subscribed for {@code event}'s class, and
 * {@code event} is not already a {@link DeadEvent}, it will be wrapped in a
 * DeadEvent and reposted.
 *
 * @param event  event to post.
 */


